This invention relates to apparatus for and a method of adding toner to the toner hopper of an electrostatic reproduction machine.
In conventional xerography, a xerographic surface comprising a layer of photoconductive insulating material affixed to a conductive backing is used to support electrostatic latent images. In the process, the xerographic surface is electrostatically charged, and the charged surface is then exposed to a light pattern of the image being reproduced to thereby discharge the surface in the areas where light strikes the surface. The undischarged areas of the surface thus form an electrostatic charge pattern (the latent image) conforming to the original pattern.
The latent image is then developed by contacting it with a finely divided electrostatically attractable powder referred to as toner. The toner is held on the image areas by the electrostatic charge on the photoconductive layer. Where the charge is greater, the greater amount of toner is deposited. Thus, a toner image is produced in conformity with a light image of the copy being reproduced. Generally, the developed image is then transferred to a suitable transfer member and affixed thereto to form a permanent record of the original document.
The latent image is developed by a suitable developer such as a magnetic brush developer. During the reproduction process, the toner in the developer is depleted. Thus, additional toner is periodically automatically dispensed into the developer by a toner hopper. Consequently, toner must also be added periodically to the toner hopper. Prior art arrangements for adding toner into a toner hopper require that toner be poured out of a container into the hopper; there are no connections between the container and the hopper. Toner is generally black and of small particle size. Unless extreme precaution is taken in pouring the toner, a cloud of fine toner is produced and toner is invariably deposited on the hands and clothing of the operator. This is highly undesirable because the powder is difficult to remove because of its small particle size. Also, in attempting to empty all of the toner from the toner container into the toner hopper, the operator may have to shake the toner container and/or tap the toner container against the toner hopper. This may result in spilling toner on the inside of the reproduction machine and in generating additional toner clouds, thus contaminating the interior of the reproduction machine.
Another prior art arrangement utilizes a toner bottle combined with a flexible conduit, the latter being connected to the toner bottle and to the toner hopper. The toner bottle is uprighted, and the toner passes through the conduit into the toner hopper. Like the above described arrangement this arrangement is also time consuming in that the toner bottle must still be shaken in attempting to empty all of its contents into the toner hopper. Also, if the hopper is filled before all of the contents of the toner bottle have been emptied, the operator is faced with the problem of disconnecting the conduit from the toner hopper without spilling toner within the machine. The toner contained within the conduit is almost invariably spilled on internal machine parts and/or the operator, thus producing the same contamination described above.
Thus, what is needed is an arrangement whereby toner can be quickly added to the toner hopper. The apparatus should be simple, easy to use, and should eliminate or minimize the danger of contaminating the inside of the reproduction machine or the operator.